KR101359139B1 - Image display device, image displaying method, plasma display panel device, program, integrated circuit and recording medium - Google Patents

Abstract

In an image display apparatus using phosphors having an afterglow time, it is a task to reduce the motion blur of the image due to the afterglow of the phosphor, and to improve the color shift of the motion blur due to the difference in the afterglow time of each phosphor. .

The image display device 1 includes a motion detector 2 that obtains motion information such as a motion area, a speed, a direction, and a matching error from an input image signal, and an input image signal due to afterglow based on the motion information. And a correction signal calculation section 3 for calculating a correction signal for correcting motion blur, and a correction section 4 for correcting an input image signal using the correction signal.

Description

Image display device, image display method, plasma display panel device, program, integrated circuit, and recording medium {IMAGE DISPLAY DEVICE, IMAGE DISPLAYING METHOD, PLASMA DISPLAY PANEL DEVICE, PROGRAM, INTEGRATED CIRCUIT AND RECORDING MEDIUM}

The present invention relates to an image display apparatus and an image display method for displaying an image using a phosphor having an afterglow time.

Image display devices such as plasma display panels (hereinafter referred to as PDPs) use three colors of phosphors (red, green, and blue), but the afterglow times are different. The blue phosphor has a short afterglow time of several microseconds, while the red and green phosphors have a long time of tens of milliseconds until the afterglow amount reaches 10% or less.

First, afterglow of this phosphor and gaze movement cause motion blur (hereinafter, referred to as afterglow motion blur) of an image.

And, because of the afterglow motion blur, when an object displayed by light emission of phosphors having different afterglow times moves, a color shift (hereinafter, referred to as color shift) of the afterglow motion blur occurs.

Hereinafter, the principle of afterglow motion blur and its color shift will be described.

First, retinal integration will be described.

Human vision integrates and perceives the amount of light that enters the eye on the retina, and feels the brightness and color by the integrated value (hereinafter referred to as retinal integration). In the PDP, gray scales are expressed by changing the light emission time without changing the brightness of light emission using the principle of retinal integration.

1 is an explanatory diagram illustrating retinal integration of each color in a stationary state of an image signal of a white dot of 1 pixel. 1, the afterglow motion blur does not occur when the light emission time distribution of the PDP, its retinal integration, and when the line of sight does not move.

Light emission of one field of the PDP basically consists of, for example, signal components by subfields having 10 to 12 shades of light, followed by afterglow components. However, blue phosphors have an extremely short afterglow time. Therefore, below, it is assumed that only a blue fluorescent substance does not have an afterglow component. Fig. 1 (a) shows light emission during one field period of white 1 pixels (hereinafter, denoted as red: 255, green: 255, blue: 255) in which the values of still red, green, and blue image signals are all 255. Time distribution is shown. That is, the red afterglow component 204 follows the red signal component 201, the green afterglow component 205 follows the green signal component 202, and the blue phosphor emits only the blue signal component 203.

Each of the red, green, and blue phosphors emits light in the retina as shown in Fig. 1B. That is, the red signal component 201 and the red afterglow component 204 are integrated into the retina in the gaze direction 206 at the time of fixation of the eye, so that the integration amount 207 of the red signal component on the retina and the red afterglow component on the retina are respectively The integral amount 210 is obtained, and the sum thereof is perceived by the human eye as a red color. Similarly, the green signal component 202 and the green afterglow component 205 are integrated into the retina so that the integration amount 208 of the green signal component on the retina and the integration amount 211 of the green afterglow component on the retina are respectively summed. As green, it is perceived by human vision. Finally, the blue signal component 203 is integrated into the retina, resulting in an integrated amount 209 of the blue signal component on the retina, which is perceived by human vision as blue.

Since the retinal integration amounts of these red, green, and blue colors are the same, the red signal signal 209 is red, and the blue signal component 209 is red by the amount of the red afterglow component 210 and the green afterglow component 211. More than signal component 207 and green signal component 208. In other words, the blue signal component of the PDP has higher luminance even if the red and green signal components and the image signal have the same value.

In this manner, when the gaze is stopped, the afterglow motion blur does not occur.

However, when there is motion, when the phosphor having afterglow components such as red and green emits light, motion blur occurs. In addition, when a phosphor that does not have an afterglow component such as blue is also emitted to display an object, a problem of color shift is caused by the difference in the light emission time distribution of each phosphor.

2 is an explanatory diagram illustrating retinal integration of each color in a gaze tracking state of a one-pixel white image signal. It demonstrates using FIG.

Fig. 2 (a) shows that one pixel of white dots (red: 255, green: 255, blue: 255) is horizontal to the right at any constant speed against a black background (red: 0, green: 0, blue: 0). The light emission time distribution for two field periods in the case of shift is shown. However, even if it is moving, each light emission does not change in the time of FIG. 1A and one field period. That is, the red afterglow component 304 · 309 follows the red signal component 301 占 306, the green afterglow component 305 占 310 follows the green signal component 302 占 307, and the blue phosphor is the blue signal. Only component 303 占 308 emits light.

Fig. 2 (b) shows the integral amount of each color of the retina on t = T to 2T (T represents one field period) at the time of fixing the eye (the eye direction 311). At this time, the red afterglow component 304 and the green afterglow component 305 are retina components at positions 312 · 313 at t = T to 2T. In addition, the red signal component 306 and the red afterglow component 309 are integrated in the retina at the same position, and become integral amounts 314 · 317, respectively. Similarly, the green signal component 307 and the green afterglow component 310 are integrated in the retina at the same position, and become integral amounts 315 占 318, respectively. The blue signal component 308 is then integrated into the retina to be the integral amount 316. As a result, afterglow of only red and green leaves in the position of integral amount 312 占 313, and a color shift occurs as a result, and it looks yellow. However, since it is a fairly short period of one field period, it is not a problem.

However, when the line of sight tracks the movement of the white point of one pixel, afterglow motion blur occurs, and as a result, a problem of color shift occurs, using Fig. 2 (c).

Fig. 2 (c) shows the integration amount of each color on the retina at t = T to 2T at the time of eye tracking (viewing direction 319). Since the line of sight follows continuously, the line of sight moves continuously to the right with time as in the line of sight 319. Thereby, each color is integrated with the retina in the direction of the eye 319. That is, the red signal component 306, the green signal component 307, and the blue signal component 308 are respectively retina integrated like the integral amounts 320, 321, and 322, and the red afterglow component 304. The afterglow component 305 占 0 is integrated in the retina, as in the tailing, like the integral amounts 323 and 324 at t = T to 2T, respectively. As a result, it is seen on the retina as shown in Fig. 2 (d). That is, the signal component of each color on the retina is 320 · 321 · 322, the signal component is slightly blue and looks like an integral amount 325, and the afterglow component is yellow by the afterglow component 323 · 324 on the retina. It looks like tailing, like the integral amount 326. When the line of sight is tracked, since it is continuously integrated over several fields, the problem of afterglow motion blur and its color shift becomes more noticeable, and subjectively deteriorates image quality than when the line of sight is fixed.

Thus, although only one pixel of white is originally moved, when the eye tracks the movement, a color shift occurs that the signal component is slightly blue and the afterglow component appears yellow with respect to the direction of the movement.

This is the principle of the afterglow motion blur and the color shift that occur when an object displayed by the light emission of a phosphor having an afterglow component moves.

And when this becomes a several pixel, ie, an image, superimposition of the afterglow motion blur of this each pixel and its color shift will occur.

FIG. 3 is an explanatory diagram illustrating retinal integration for each signal component and afterglow component in the state where the eye of a white square object is tracked on a gray background. FIG. 3 (a) shows an image signal projected on a PDP, with a gray background (red: 128, green: 128, blue: 128), and a white square object (red: 255, green: 255, blue: 255). Indicates the state of moving horizontally to the right at a constant speed.

Next, Fig. 3B shows one horizontal line from the image signal of Fig. 3A and shows the time distribution in one field period of light emission. That is, the signal component 401 emits light, after which the afterglow component 402 continues, and afterglow leaks into the next field.

When the gaze tracks the movement of the white square object, the gaze is continuously followed, so the gaze 403 continuously moves to the right with time. The retina integration is performed in this visual direction, the integration with respect to the component S1 of the signal component 401 is performed at the position P1, and the integrated amount I1 is calculated. In addition, the integration of the component S2 of the signal component 401 is performed at the position P2, and the integral amount I2 is performed of the integration of the component S3 of the signal component 401 at the position P3. And the integral amount I3 is integrated to the component S4 of the signal component 401 at the position P4 and the integral amount I4 is the component S5 of the signal component 401 at the position P5. ), The integral amount I5 is performed at the position P6, and the integral amount I6 is performed at the position P6, and the integral amount I6 is performed at the position P7. Integral is performed on component S7 of 401 and integral amount I7 is performed on component S8 of signal component 401 at position P8 to calculate integral amount I8, As a result, the signal component 401 becomes the retinal integration amount 404 of the signal component shown in Fig. 3C. Further, at position P1, integration is performed on component S11 of afterglow component 402, and integral amount I11 is performed, and at position P2, integration on component S12 of afterglow component 402 is performed. Integral amount I12 is integrated to component S13 of afterglow component 402 at position P3, and integral amount I13 is component S14 of afterglow component 402 at position P4. ) Is integrated, the integral amount I14 is integrated at the position P5 to the component S15 of the afterglow component 402, and the integral amount I15 is at the position P6. Integral with respect to component S16 of 402 is performed and integral amount I16 is performed, and with position P7, integral with component S17 of afterglow component 402 is performed, and integral amount I17 is represented with the position ( In P8), the integration of the afterglow component 402 to the component S18 is performed and the integral amount I18 is calculated. As a result, the afterglow component 402 is the retinal integration amount of the afterglow component shown in FIG. 405).

Here, originally, only a white object moves on a gray background, and a color such as blue or yellow should not occur. As described above, since the white color by the signal component of the PDP is slightly blue, the afterglow component is yellow, and looks white by the sum of these, the retinal integration amount 404 of the signal component and the retinal integration amount of the afterglow component ( 405) requires an integral value proportional to each coordinate position. However, as shown in Fig. 3 (d), excessive or insufficient (hereinafter, referred to as afterglow motion blur component) occurs in the afterglow component. That is, in FIG. 3 (a), the afterglow of FIG. 3 (d) is excessive in the vicinity of the area where the value of the red or green image signal is reduced from the previous field to the current field (hereinafter referred to as the luminance reduction area) 406. An amount 408 appears and appears yellow, whereas an afterglow deficiency 409 appears and appears blue around a region where a value of a red or green image signal is increased from the previous field to the current field (hereinafter referred to as a luminance increase region) 407. .

This is the principle of afterglow motion blur in the image and its color shift.

In Patent Literature 1, a pseudo afterglow having a cutting line characteristic equivalent to red and green phosphors is created from a current field for color shift caused by excessive afterglow around the luminance reduction region. In addition to the current field, a method of reducing color shift has been proposed.

[Patent Document 1: Japanese Patent Laid-Open No. 2005-141204]

(Problems to be Solved by the Invention)

However, the method proposed in Patent Literature 1 adds a blue pseudo afterglow signal to the current field. Thus, for example, when the area to which a blue pseudo afterglow signal is added is calculated correctly, an excessive amount of afterglow is taken as an example of FIG. A blue pseudo afterglow signal is added to the area where 408 occurs. That is, since the integration amount of the blue pseudo afterglow signal is added to the integration amounts of the red afterglow component and the green afterglow component, the color shift is eliminated. However, it is not unchanged to cause an amount of integration that is not necessary inherently, and adding a blue pseudo afterglow signal to the current field is not different from actively adding motion blur to a blue image signal. For this reason, there is a problem that the blur increases. In addition, the area | region in which the afterglow shortage amount 409 arises was not considered.

The present invention relates to an image display apparatus using a phosphor having an afterglow time, and an object thereof is to provide an image display apparatus and an image display method capable of reducing the afterglow motion blur itself caused by movement.

(MEANS FOR SOLVING THE PROBLEMS)

In order to achieve the above object, an image display apparatus according to the present invention is an image display apparatus that displays an image using a phosphor having an afterglow time, and includes motion detection means for detecting motion information from an input image signal, and the motion. A correction signal calculating means for calculating a correction signal for correcting image quality deterioration caused by the afterglow and the movement of the image signal based on the information, and correction means for correcting the image signal by the correction signal. It is characterized by.

As a result, afterglow motion blur components are corrected only for image signals corresponding to phosphors having an afterglow time, generally red and green image signals, so that the motion blur due to the afterglow caused by the movement of the eye can be precisely corrected. You can correct it. As a result, the color shift problem of the afterglow motion blur can be fundamentally solved, and no color shift occurs.

Here, afterglow time is a time required, for example, after the phosphor emits light until the amount of light decays to 10% or less immediately after the light emission.

The motion information is a motion area, a direction of motion, a speed, a matching error at the time of motion detection, and the like. Here, the movement area is an area in which an object in the input image has moved, for example, from the previous field to the current field.

The deterioration in image quality corresponds to the blur of afterglow motion of an object displayed by light emission of a phosphor having an afterglow component. When the moving object is displayed by light emission of a plurality of phosphors having different afterglow time, the moving object includes a color shift generated as a result of the afterglow motion blur.

The correction signal corresponds to an afterglow motion blur component. In addition, a movement area | region may be any of a pixel unit or the area unit which consists of a some pixel, for example.

The motion detecting means detects a motion region of the image signal as the motion information, and the correction signal calculating means includes a region in which the value of the image signal is reduced from the previous field among the motion region and its peripheral region; In the peripheral area, a correction signal for attenuating the image signal may be calculated.

In the present invention, the previous field indicates a field before the current field and is not limited to only one field before.

As a result, the afterglow motion blur in the luminance reduction region and the surrounding area can be reduced, and incidentally, for example, the color shift of the yellow afterglow motion blur seen when visually tracking the movement of a white object can be corrected. . The motion detecting means detects a motion region of the image signal as the motion information, and the correction signal calculating means includes a region in which the value of the image signal increases from the previous field among the motion region and its peripheral region; In the peripheral area, a correction signal for amplifying the image signal may be calculated.

As a result, the afterglow motion blur in the luminance increasing region and the surrounding area can be reduced, and incidentally, for example, the color shift of the blue afterglow motion blur seen when the movement of a white object is tracked can be corrected. . The motion detecting means further calculates a motion speed of the motion area, and the correction signal calculating means changes the amount of change in the current field and all fields of the image signal in the motion area and its surrounding area. You may correct according to the speed and calculate the corrected value as said correction signal.

Here, the previous field is, for example, a field one field before the current field.

In order to accurately calculate the afterglow motion blur component according to the principle, it is correct to calculate only the current field as described earlier with reference to FIG. 3. However, this requires the integration of the afterglow component that is attenuated by the exponential function with the movement of the line of sight, resulting in a problem such as a large circuit size. Thus, by correcting the amount of change in the signal of the current field and the previous field based on the movement speed, a correction signal is approximated to correct the afterglow motion blur. This makes it possible to perform correction on a small circuit scale. In addition, the correction signal calculating means may modify the amount of change by performing a low pass filter process with the number of taps corresponding to the movement speed. Further, the motion detecting means further calculates the direction of motion of the motion area, and the correction signal calculating means corrects the amount of change asymmetrically according to the motion speed and the direction of the motion, thereby correcting the value. May be calculated as the correction signal.

Here, the correction asymmetric with respect to the direction of the movement is, for example, weighted correction so that the correction intensity in the direction of the movement becomes stronger. Since the afterglow attenuates with an exponential function and integrates the retina with the eye movement, a portion with a large amount of light of the afterglow component appearing in time is strongly perceived in front of the movement direction of the eye. Therefore, the correction signal must be asymmetrical with respect to the direction of the movement so that the correction signal can be made stronger with respect to the direction of the movement. As a result, more accurate correction can be performed.

If the direction of movement is not used, there is a possibility that unnecessary correction is performed, such as correction in a direction opposite to the movement. By using the direction of movement, the correction can be performed with high precision. Further, the correction signal calculating means performs the low pass filter processing on the change amount with the number of taps corresponding to the speed of the movement, and further, in the direction of the movement with respect to the low pass filter pass signal subjected to the low pass filter processing. Therefore, it may be asymmetrically corrected by multiplying a signal prepared using two straight lines and one quadratic function.

Here, the method of shaping the correction signal by using two straight lines and one quadratic function is one example, and any correction signal value in front of the direction of the movement may be larger.

Further, the motion detecting means further calculates the motion information related to the motion region and the motion information reliability indicating the reliability of the motion information, and the correction signal calculating means indicates that the lower the reliability of the motion information, the correction signal is. May be attenuated.

Here, the motion information is, for example, a motion speed, a direction, a motion vector, an error (hereinafter referred to as an error) calculated at the time of motion vector detection in a moving image. The error refers to, for example, the total sum (absolute value error total) of the absolute value of the pixel difference between the two-dimensional block of the current field and the two-dimensional block of the reference field used in two-dimensional block matching or the like. The motion detection means is a means for outputting motion information and may be, for example, two-dimensional block matching. The motion information reliability is a value lowered when the reliability of the motion detection is low or when the correlation between the motion information and the human eye's tendency to track is low.

Motion detection is not able to detect actual motion perfectly, and even if it can detect perfectly, it is not necessarily tracked by human eyes. Therefore, when there is a high likelihood of detecting erroneous motion by motion detection, it is possible to suppress unnecessary correction (hereinafter, side effects) by attenuating the correction signal.

The motion detecting means may calculate the motion speed of the motion area as the motion information, and calculate the reliability of the motion information as the motion speed increases.

That is, the correction is weak when the movement is too fast. Human vision tends not to track too fast movements. In addition, if the correction fails in too fast a movement, side effects occur widely. In such a case, the side effect can be suppressed by weakening the correction effect.

The motion detecting means may calculate the error of the corresponding area of the current field and the previous field as the motion information, and calculate the lower the reliability of the motion information as the error is larger.

That is, when the error is large, the correction is weakened. The motion detection sometimes fails, and when the error is large, the motion detection is likely to fail. In such a case, the side effect can be suppressed by weakening the correction effect.

The motion detecting means calculates the error of the corresponding area of the current field and the previous field and the error of the peripheral area of the corresponding area as the motion information, and the smaller the difference between the two errors is, the higher the motion information reliability is. You may calculate so that it may become low.

That is, the correction is weakened when an error is detected in the direction of movement. When motion detection sometimes fails, and when the difference between the detected motion information and the error of the surroundings, for example, the motion information on the opposite side is small, the reliability of the motion direction is low. In such a case, the side effect can be suppressed by weakening the correction effect.

The motion detecting means calculates the motion speed and the direction of the motion as the motion information, and calculates the motion speed and the direction of the motion and the motion speed and the motion of the peripheral area of the motion area. The larger the difference in the direction, the lower the reliability of the motion information may be calculated.

Here, the difference between the movement speed of the peripheral region and the direction of the movement, for example, in the case of two-dimensional block matching, is the target block motion vector and the motion of the block adjacent to the calculated upper, upper right and left sides. It is the difference of the mean vectors of the vectors. This difference may be obtained from the inner product of the target motion vector and the average motion vector around it.

That is, the correction is weakened when the difference between the target motion and the surrounding motion is large. Human vision often sees the average movement around when multiple small objects are moving in various directions. In such a case, the side effect can be suppressed by weakening the correction effect.

Further, the motion detecting means calculates the motion speed and the direction of the motion of the motion area as the motion information, and calculates the speed of the motion and the direction of the motion and the motion speed and the motion of the corresponding area of all fields. The larger the difference in the direction, the lower the reliability of the motion information may be calculated.

Specifically, for example, in the case of two-dimensional block matching, the motion vector difference between the target two-dimensional block and the two-dimensional block in the field before the current field indicated by the motion vector is used. This difference may be obtained from the inner product of both vectors.

In other words, the correction signal is attenuated when the movement of any region changes significantly during the two field periods. Human vision tends to track movements over a period of time, and not movements that do not. In such a case, the side effect can be suppressed by weakening the correction effect. In addition to the movement during the two field periods, a change in the movement during more field periods may be used. Moreover, you may calculate the time change of both motion vectors, and consider the acceleration vector of a motion.

In addition, each structure mentioned above can be combined with each other, unless the meaning of this invention deviates.

In addition, the present invention can be realized not only as such an image display apparatus but also as an image display method using the characteristic means included in such an image display apparatus as a step or as a program for executing those steps on a computer. have. It goes without saying that such a program can be distributed through a recording medium such as a CD-ROM or a transmission medium such as the Internet.

(Effects of the Invention)

According to the image display device and the image display method according to the present invention, it is possible to reduce the afterglow motion blur in an image display device using a phosphor having an afterglow time. Incidentally, the color shift of the afterglow motion blur can be reduced with respect to the motion of the displayed object by emitting light of a plurality of light emitting bodies having different afterglow time.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is an explanatory diagram illustrating the retinal integration of each color in the stationary state of an image signal of a white pixel of one pixel, and (a) the light emission distribution in the time direction during one field period, and (b) the amount of integration on the retina. The figure shown.

2 is an explanatory diagram illustrating retinal integration of each color in a gaze tracking state of a one-pixel back image signal, (a) light emission distribution in the time direction for two field periods, and (b) t at eye fixation = Integral amount of each color on the retina at T ~ 2T, (c) Integral amount of each color on the retina at t = 2T at eye tracking, (d) At t = T-2T at eye tracking It is a figure which shows the visible method of a retina.

3 is an explanatory diagram illustrating retinal integration for each signal component and afterglow component in a state where the eye of a white square object is traced on a gray background, (a) a display pattern (movement) on the PDP, (( b) the light emission distribution in the time direction during one field period of one horizontal line of the image signal of (a), (c) the amount of retinal integration of signal components on the retina during eye tracking, and (d) afterglow on the retina during eye tracking It is a figure which shows the retinal integration amount of a component.

4 is a block diagram showing the configuration of an image display device of a basic embodiment of the present invention.

5 is a diagram showing a specific application example of the image display device of the present invention.

6 is a block diagram showing the configuration of the image display device of the first embodiment.

7 is an explanatory diagram for explaining the flow of processing in the image display device of the first embodiment, (a) previous field, (b) current field, (c) subtracted signal (all field-string field), (d) Subtracted signal LPF pass signal, (e) asymmetric gain, (f) correction signal, (g) current field after correction.

8 is a block diagram illustrating a structure of a motion information reliability calculator.

9 is a block diagram showing the configuration of the image display device of the second embodiment.

10 is a block diagram showing the configuration of the image display device of the third embodiment.

11 is an explanatory diagram for explaining the flow of processing in the image display device of the third embodiment, (a) previous field, (b) current field, (c) subtracted signal (all field-string field), (d) A diagram showing the motion area, (e) the current field LPF pass signal, (f) the absolute value signal of the subtraction signal of the current field and the current field LPF, (g) the LPF pass signal of the absolute value signal, and (h) the current field after correction. to be.

12 is a block diagram showing the configuration of the image display device of the fourth embodiment.

DESCRIPTION OF THE REFERENCE NUMERALS

1 image display device

2 motion detector

3 correction signal calculator

4 correction unit

201, 301, 306 red signal component

202, 302, 307 green signal component

203, 303, 308 blue signal component

204, 304, 309 Red Afterglow Components

205, 305, 310 Green Afterglow Components

206, 311 Eye direction at eye fixation

207 Integral amount of red signal component on retina

208 Integral amount of green signal component on retina

209 Integral amount of blue signal component on the retina

210 Integral amount of red afterglow on retina

211 Integration of Green Afterglow Components on the Retina

312 Integral amount of retina image of component which red afterglow component from all fields leaked in period of t = T-2T at the time of fixation

313 Integral amount of retinal image of component which green afterglow component from all fields leaked in during period of t = T-2T at eye fixation

314 Integral amount of red signal component on the retina during the period of t = T ~ 2T at eye fixation

315 Integral amount of green signal component on retina of period of t = T-2T at fixation

316 Integral amount of blue signal component on the retina during the period of t = T ~ 2T at eye fixation

317 Integral amount of red afterglow component on the retina during the period of t = T-2T

318 Integral amount of green afterglow component on the retina during the period of time t = T ~ 2T

319 Eye Movement Direction in Eye Tracking

Integral amount of the red signal component on the retina during the period of t = T-2T

321 Integral amount of green signal component on the retina of the period t = T-2T at eye tracking

322 Integral amount of blue signal component on the retina during the period t = T ~ 2T at eye tracking

323 Integral amount of red afterglow component on the retina during the period of t = T-2T during eye tracking

324 Integral amount of green afterglow component on the retina of the period t = T-2T at the time of eye tracking

325 Method of seeing signal component on retina of period of t = T-2T at eye tracking

326 Method of seeing afterglow component on retina of period of t = T-2T at eye tracking

401 signal component

402 afterglow component

403 Eye Movement Direction in Eye Tracking

404 Integral amount of signal component on the retina during eye tracking

405 Integral amount of afterglow components on the retina during eye tracking

406 Luminance Reduction Zone

407 luminance increase range

408 Excessive Afterglow Around the Luminance Area

409 Afterglow shortage around luminance increase area

Example of correction signal shape by subtraction of red and green image signals around 410 luminance reduction area

Example of correction signal shape by addition of red and green image signals around 411 luminance increase area

Example of correction signal shape by addition of blue image signal around 412 luminance reduction area

Example of correction signal shape by subtraction of blue image signal around 413 luminance increase area

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600 Image display device of the first embodiment

601 1 Field Delay

602, 608, 611 subtractor

603, 612 motion detector

604 LPF (Low Pass Filter)

605 asymmetric gain calculator

606 motion information reliability calculator

607 multiplier

609 motion information memory

613 adder

701 Straight line in front of the motion area at asymmetrical gain

Quadratic Function of the Motion Region at Asymmetric Gain

703 Straight Line in the Motion Region at Asymmetric Gain

801 first gain calculating unit

802 coordinate average calculation unit

803 minimum value selection

804 Second Gain Calculator

805 difference absolute value calculator

806 Third gain calculator

807 Motion Vector Creator

808 Peripheral Vector Computation

809 4th gain calculator

810 fifth gain calculator

811 multiplier

900 Image display device of the third embodiment

901 1 Field Delay

902, 905, 909, 911 Subtractor

903 motion detector

904, 907 LPF (Low Pass Filter)

906 absolute value calculator

908 Correction signal area limit

912 adder

The basic form of embodiment of this invention is described, and four embodiment which limited each structure with respect to the basic form is demonstrated.

First, the structure of the basic form of embodiment of this invention is demonstrated using FIG. 4 is a block diagram showing the configuration of an image display device of the basic embodiment of the present invention, and FIG. 5 is a diagram showing a specific application example of the image display device. The image display apparatus 1 is an image display apparatus which displays an image using red and green phosphors having an afterglow time and blue phosphors having almost no afterglow time. A motion detector (2) for detecting motion information such as direction and matching errors, a correction signal calculator (3) for calculating correction signals for red and green image signals using input image signals and motion information; And a correction unit 4 for correcting the input image signal using this correction signal. Specifically, this image display device 1 can be applied to the plasma display panel 10 shown in FIG. 5, for example. This basic form can reduce afterglow motion blur.

Next, four embodiments in which the motion detection unit 2, the correction signal calculation unit 3, and the correction unit 4 of the basic form are limited will be described. Here, there are four embodiments in which the shape of the correction signal is different around the luminance reducing region and around the luminance increasing region, and in the case of high-precision correction using the direction of movement and without detecting the direction of movement, This is because correction may be performed at a hardware scale, and there are four embodiments based on a combination thereof.

That is, Embodiment 1 "the form which correct | amends the periphery of a brightness reduction area | region by using the direction of a movement", Embodiment 2 "the form which correct | amends the periphery of a brightness increase area | region using the direction of a movement", Embodiment 3 "the movement of The form which correct | amends the periphery of a luminance reduction area | region without using a direction ", and Embodiment 4" The form which correct | amends the periphery of a brightness | luminance increase area | region without using the direction of a movement ".

Hereinafter, these four embodiments are described in order.

(Embodiment 1)

Embodiment 1 of the image display apparatus of this invention is demonstrated using FIG. 6, FIG.

In Embodiment 1, the afterglow motion blur component around the luminance "reduction" area is calculated for the image signals of each color, and the correction signal is "subtracted" from the current field for the "red, green" image signal having a long afterglow time. It aims at reducing the afterglow motion blur. At the same time, an object thereof is to reduce color shift.

This is common to the first to fourth embodiments, but the processing is performed for each horizontal line in order to reduce the hardware scale.

6 is a block diagram showing the configuration of the image display device of the first embodiment. The image display device 600 according to the first embodiment includes one field retarder 601, a motion detector 603, a subtractor 602 占 608, a low pass filter (hereinafter referred to as LPF) 604, and asymmetric gain calculation. A unit 605, a motion information reliability calculator 606, a multiplier 607, and a motion information memory 609 are provided. Here, the input / output of each component is one horizontal line of the red, green, and blue image signals.

The one field delay unit 601 delays the input current field by one field period, and outputs all fields corresponding to one field period before the current field. The subtractor 602 subtracts the current field from all fields, and outputs a subtraction signal of only both components. The motion detection unit 603 performs motion detection using the input current field, all fields, and the subtraction signal, and outputs motion information (motion area, direction, speed, error). The LPF 604 outputs the subtracted signal LPF pass signal by applying the tap number LPF obtained from the speed of the movement to the input subtracted signal. The asymmetric gain calculator 605 outputs an asymmetric gain for shaping the subtracted signal LPF pass signal using the input motion information. The motion information reliability calculation unit 606 includes motion information, motion information of three lines adjacent to the upper side with respect to the line under processing, output from the motion information memory 609, and all fields corresponding to the motion information to be targeted. The motion information reliability is calculated using the motion information of the region of. The multiplier 607 calculates the subtracted signal LPF pass signal output from the LPF 604, the asymmetric gain output from the asymmetric gain calculator 605, and the motion information reliability gain output from the motion information reliability calculator 606. Multiply and output the correction signal. The subtractor 608 subtracts the correction signal from the current field only for the red and green image signals, and outputs the current field in which afterglow motion blur is corrected. The motion information memory 609 is a memory that stores the detected motion information.

7 (a) to 7 (g) are explanatory diagrams for explaining the processing flow of the image display device of the first embodiment. 7 (a) to 7 (g), each signal for producing a correction signal for a red or green image signal of one horizontal line and the change thereof are shown.

Hereinafter, the detail of the process of Embodiment 1 is described.

The image display device 600 of the first embodiment inputs one horizontal line of the current field, and outputs one horizontal line of the current field in which afterglow motion blur is corrected.

First, all fields are calculated.

The one field delay unit 601 delays the input current field by one field period, and outputs all fields corresponding to one field period before the current field. 7 (a) and 7 (b) show the previous field and the current field, respectively.

Second, a subtracted signal is calculated from the previous field and the current field.

The subtractor 602 subtracts the current field from all fields, and outputs a subtraction signal of only both components. Fig. 7C shows this subtraction signal.

The subtraction signal is used here because the afterglow motion blur component resembles the subtraction signal in principle.

In addition, the present invention is not limited to subtraction, so long as the afterglow motion blur component can be approximately calculated, such as deforming the current field itself and deforming the field before the current field.

Third, motion information is detected from the previous field, the current field, and the subtracted signal.

The motion detection unit 603 performs motion detection using the input current field, all fields, and the subtracted signal, and outputs motion information (motion area, direction, speed, error).

First, the motion detector 603 detects a motion area and calculates a speed. That is, the motion detection unit 603 sets a region in which one or both of the red and green subtracted signals exceed a predetermined threshold value as the movement region, and sets the width as the movement speed. As a result, the luminance reduction region can be set as the movement region. In addition, since the motion search such as two-dimensional block matching is not performed, for example, the circuit scale can be suppressed and the area and speed of the motion can be detected.

Next, the motion detector 603 calculates an error and detects a direction. That is, the motion detection unit 603 includes the absolute value error sum total (hereinafter, referred to as SAD (hereinafter referred to as SAD) for each of the motion area in the previous field and the areas of the same width on the left and right sides with respect to the motion area in the current field. Sum of Absolute Difference). These are called left SAD, right SAD, for example. At this time, the SAD to be obtained is, for example, the total sum of errors that are image signals of red, green, and blue. When the left SAD is smaller than the right SAD, the motion detection unit 603 sets the direction of movement to the left, and when the right SAD is smaller than the left SAD, the motion detection unit 603 sets it to the right, and when the left SAD and the right SAD are the same. Assumes no movement. Here, the correction is not performed when there is no movement.

In addition, the motion detection part 603 is not limited to this method, As long as it detects at least the direction and speed of a movement, for example, two-dimensional block matching, it is good.

Fourth, the LPF is applied to the subtracted signal, and the subtracted signal LPF pass signal is calculated.

The LPF 604 receives a subtraction signal and motion information. The LPF 604 applies the tap number LPF obtained from the speed of the movement to the input subtracted signal, and outputs the subtracted signal LPF pass signal. 7 (d) shows a subtracted signal LPF pass signal. Here, the number of taps is used as the speed of movement (pixel / field), and the LPF is calculated by calculating an average of peripheral pixel values, but is not limited thereto.

The LPF is used here because, in principle, the afterglow motion blur component has an enlargement by the retina integration in the line of sight, and thus a process corresponding to this is required. In addition, the LPF may not be used as long as it is a process of spatially widening the subtracted signal.

Fifth, an asymmetric gain is calculated from the motion information.

The asymmetric gain calculator 605 outputs an asymmetric gain for shaping the subtracted signal LPF pass signal using the input motion information. Here, the asymmetric gain calculation unit 605 creates the asymmetric gain as two straight lines and one quadratic function, for example, as shown in Fig. 7E. That is, the asymmetric gain calculator 605 is a straight line 701 in the area (in this case right side) in front of the motion area, and the quadratic function part 702 in the motion area. And the combination of the straight portions 703. In addition, the range of these values shall be 0.0-1.0. At this time, since it is necessary to grasp the front of the movement area, the direction of the movement is necessarily required to create an asymmetric gain.

The use of asymmetric gain here is, in principle, for afterglow motion blur, as tailing, appears strongly forward in the direction of motion, and thus strongly corrects forward. Thereafter, by multiplying the asymmetrical gain by the subtracted signal LPF signal, for example, an afterglow excess amount 408 around the luminance reduction region shown in Fig. 3D is created.

In addition, although the shape of the asymmetric gain of FIG. 7 (e) is the shape of FIG. 3, FIG. 6, since the afterglow motion blur component changes with the input current field, it is not limited to the shape of FIG. 7 (e). For example, as the speed of movement increases, the shape of the asymmetric gain can be made wider in the lateral direction. This is because the faster the movement speed is, the larger the area causing deterioration of image quality, and the larger the area requiring correction.

Sixth, the motion information reliability gain is calculated from the motion information.

The motion information reliability calculation unit 606 is configured to display motion information of three lines adjacent to the upper side of the line during processing, outputted from the motion information and the motion information memory 609, and a field before the corresponding motion information. The motion information reliability is calculated using the motion information of the area. However, in FIG. 7, since the motion information reliability is assumed to be 1.0, there is no description of the motion information reliability in FIG. 7.

8 is a block diagram showing the detailed configuration of the motion information reliability calculation unit 606. The motion information reliability calculation unit 606 outputs a product of five gains (hereinafter, first to fifth gains), and as shown in FIG. 8, the first gain calculation unit 801 and the coordinate average calculation unit 802a. 802b, minimum value selector 803, second gain calculator 804, absolute difference value calculator 805, third gain calculator 806, motion vector generator 807, peripheral vector calculator 808, a fourth gain calculator 809, and a fifth gain calculator 810.

Hereinafter, each gain is explained in full detail.

The first gain is described. The first gain relates to the speed of movement.

The first gain calculator 801 is a value that changes linearly from 1.0 when the input movement speed is smaller than the first threshold value, and 1.0 to 0.0 when the first threshold value is greater than or equal to the second threshold value. It is a gain function of the cutting line characteristic which outputs 0.0 when it exceeds a threshold.

This makes it possible to make the correction effect weaker or not to perform the correction, such as when the movement is too fast and the possibility of side effects is high.

The second gain is described. The second gain moves and relates to the error of detection.

First, the coordinate average calculation units 802a and 802b calculate the left average SAD and the right average SAD obtained by dividing the left SAD and the right SAD by the movement area width, respectively. Next, the minimum value selection unit 803 selects these minimum values. Then, the second gain calculator 804 is a value that changes linearly from 1.0 when the inputted minimum value is smaller than the first threshold value and 1.0 to 0.0 when the first threshold value or more is less than the second threshold value. It is a gain function of the cutting line characteristic that outputs 0.0 when two thresholds are exceeded.

As a result, the larger the error of motion detection, the weaker the correction effect or no correction is performed.

The third gain is described. The third gain relates to the direction of movement.

The absolute difference value calculation unit 805 calculates the absolute difference value of the left average SAD and the right average SAD calculated by the coordinate average calculation units 802a and 802b. The third gain calculator 806 is a value that changes linearly from 0.0 when the absolute difference value input is smaller than the first threshold value and 0.0 to 1.0 when the first threshold value is greater than or equal to the second threshold value. It is a gain function of the cutting line characteristic which outputs 1.0 when it is more than 2nd threshold value.

The smaller the difference between neighboring motion information is, the lower the reliability is in the direction of the motion, whereby the correction effect can be weakened or the correction can be avoided.

In the first to third gains, all of them are used as gain functions of the cutting line characteristics, but may be set as step functions or curves using only one threshold value.

The fourth gain is described. The fourth gain relates to the isolation of the target motion information with respect to the surrounding motion information.

First, the motion vector creating unit 807 creates a motion vector from the direction and speed of the motion. Specifically, the motion vector creation unit 807 is, for example, a value labeled with "+5" when moving at a speed of 5 in the right direction and "-10" when moving at a speed of 10 in the left direction. do. This is necessary when the direction and speed of the motion are calculated separately, but it is not necessary to be a vector from the beginning such as, for example, two-dimensional block matching.

Next, the motion information memory 609 outputs the motion vectors of the regions on one line, on two lines, and on three lines in the spatially upper three lines of the line in the current processing, with respect to the movement area in the current processing. (Motion vector creation is performed by the same method as the motion vector creation unit 807), and these are input to the peripheral vector calculation unit 808. The peripheral vector calculator 808 outputs the average vector of the three input motion vectors as the peripheral vector.

For example, when motion vector detection is performed by two-dimensional block matching, the average of the motion vectors of the blocks adjacent to the calculated upper, upper right and left sides may be used as the peripheral motion vector. In this way, all of them may be used as long as spatial motion information is used.

The fourth gain calculator calculates, by an inner product, the cosine of the angle formed by the motion vector output from the motion vector creating unit 807 and the peripheral vector output from the peripheral vector calculating unit 808 using the inner product. Add 1 and divide by 2 to make a value from 1.0 to 0.0, and output this value as a fourth gain.

As a result, when the target motion vector has a large difference from the surrounding motion vector, that is, when the target motion vector is isolated from the surrounding vector, the correction effect can be weakened or the correction can be prevented. .

The fifth gain is described. The fifth gain is about the persistence of the movement.

First, a motion vector of a current field (hereinafter, referred to as a current motion vector) created by the motion vector creating unit 807 is inputted to the motion information memory 609, and motion vectors of an area of all fields corresponding to the current motion vector (hereinafter, Output all motion vectors).

Then, the fifth gain calculating unit 810 obtains the cosine of the angle formed by the input current motion vector and the full motion vector by the inner product, adds 1 to the cosine, divides it by 2, and sets a value of 1.0 to 0.0. This value is output as the fifth gain.

As a result, when the difference between the current motion vector and the previous motion vector is large, that is, when there is no persistence in the motion, the correction effect can be weakened or no correction can be made.

Then, the multiplier 811 outputs the value obtained by multiplying the first to fifth gains as the motion information reliability.

In addition, in all of the 1st-5th gains, you may make it possible to compute by bit shift for circuit scale reduction. In addition, since the 4th and 5th gains require a motion information memory, it is not necessary to use all the 1st-5th gains, such as not using.

7. A correction signal is calculated by multiplying the subtracted signal LPF pass signal by the asymmetric gain and the motion information reliability gain.

The multiplier 607 calculates the subtracted signal LPF pass signal output from the LPF 604, the asymmetric gain output from the asymmetric gain calculator 605, and the motion information reliability gain output from the motion information reliability calculator 606. Multiply and output the correction signal. Fig. 7F shows the obtained correction signal.

In addition, although not described in FIG. 6, Embodiments 1 to 4 perform independent processing for each line, and may cause processing irregularities in the vertical direction by treatment / non-treatment. In order to prevent this, you may use the IIR filter which replaces the correction signal of the line currently in process, and the processed internal signal of the correction signal on one line spatially with a current correction signal.

Eighth, the current field after correction is output from the current field and the correction signal. Fig. 7 (g) shows the current field after correction.

The subtractor 608 subtracts the correction signal from the current field only for the red and green image signals, and outputs the current field in which afterglow motion blur is corrected. According to the first embodiment, the afterglow motion blur component around the luminance "reduced" region is calculated for the image signals of each color, and the correction signal is selected from the current field for the "red, green" image signal having a long afterglow time. Subtraction ”to reduce the afterglow motion blur. At the same time, color shift can be reduced by this.

(Embodiment 2)

9 is a block diagram showing the configuration of the image display device of the second embodiment. Embodiment 2 of the image display device of the present invention partially changes the first embodiment. Only this change is explained.

In Embodiment 2, the afterglow motion blur component around the luminance "increase" area is calculated for the image signals of each color, and the correction signal is added to the current field for the "red, green" image signal having a long afterglow time. It aims at reducing the afterglow motion blur. At the same time, an object thereof is to reduce color shift.

The configuration difference with Embodiment 1 is demonstrated using FIG. 6 and FIG.

In the image display device 610 of the second embodiment, the subtractor 602, the motion detector 603, and the subtractor 608 of the image display device 600 of the first embodiment are respectively subtracted 611 and motion detector 612. Is changed to the adder 613. Hereinafter, the detail is shown.

The change of the subtractor 602 is described.

Reverse the object of subtraction. That is, the subtractor 611 subtracts all fields from the current field and outputs only a positive subtraction signal.

As a result, the luminance increase region can be used as the movement region.

The change of the motion detection part 603 is demonstrated.

The detection of the reference field and the movement direction at the time of error calculation is reversed. That is, the motion detector 612 calculates SAD for each of the motion area in the current field and the areas of the same width on the left side and the right side with respect to the motion area in the previous field. These are called left SAD, right SAD, for example. When the left SAD is smaller than the right SAD, the motion detector 612 sets the direction of movement to the right, and when the right SAD is smaller than the left SAD, the motion is detected as the left, and the left SAD and the right SAD are the same. Assumes no movement. Here, the correction is not performed when there is no movement.

The change of the subtractor 608 is described.

`Change subtraction to add. That is, the adder 613 adds the correction signal to the current field and outputs it. Here, although the current field may exceed 255 at the time of addition, this is output as 255, for example.

In principle, however, it is not correct to simply add a correction signal to the red and green image signals. This is because the afterglow shortage amount 409 around the luminance increase area of FIG. 3 needs to be added in consideration of the amount of light entering the retina as in the area 411. As this realization method, there is a method of changing the configuration of the subfield only in this part. Specifically, the red and green subfields are turned on at the position and time of the region 411.

According to the second embodiment, the afterglow motion blur component around the luminance "increase" region is calculated for the image signals of each color, and the correction signal is displayed in the current field for the "red, green" image signal with a long afterglow time. Add "to reduce the afterglow motion blur. At the same time, color shift can be reduced by this.

(Embodiment 3)

Embodiment 3 of the image display apparatus of this invention is demonstrated using FIG. 10, FIG.

In the third embodiment, the afterglow motion blur component around the luminance "reduced" region is calculated for the image signal of each color without using the direction of the movement, and for the image signal of "red, green" having a long afterglow time. It aims to reduce afterglow motion blur by "subtracting" the correction signal from the current field. At the same time, an object thereof is to reduce color shift.

10 is a block diagram showing the configuration of the image display device of the third embodiment. As shown in FIG. 10, the image display device 900 of the third embodiment includes one field retarder 901, a subtractor 902 占 905 占 909, a motion detector 903, a low pass filter 904 占 907, An absolute value calculator 906 and a correction signal region limitation unit 908. Here, the input / output of each component corresponds to one horizontal line of the red, green, and blue image signals.

The one field delay unit 901 delays the input current field by one field period, and outputs all fields corresponding to one field period before the current field. The subtractor 902 subtracts the current field from all fields, and outputs a subtraction signal of only both components. The motion detection unit 903 sets a region where the input subtracted signal exceeds a threshold value as a motion region, and outputs the width as a speed. The LPF 904 applies the LPF to the input current field and outputs it. The subtractor 905 subtracts the current field LPF pass signal from the current field. The absolute value calculator 906 calculates an absolute value of the subtracted signal of the current field and the current field LPF. The LPF 907 applies the LPF to the absolute value signal output from the absolute value calculator 906 and outputs it. The correction signal region limiting unit 908 sets all correction signal values other than the movement region peripheral region to zero. The subtractor 909 subtracts the correction signal output from the correction signal region limitation unit 908 from the current field.

11 (a) to 11 (h) are explanatory diagrams for explaining the flow of the process of the third embodiment. 11 (a) to 11 (h), each signal for producing a correction signal for a red or green image signal of one horizontal line and its change are shown. Hereinafter, the detail of the process of Embodiment 3 is shown.

The image display device 900 of the third embodiment inputs one horizontal line of the current field and outputs one horizontal line of the current field in which afterglow motion blur is corrected.

First, all fields are calculated. The one field delay unit 901 delays the input current field by one field period, and outputs all fields corresponding to one field period before the current field. 11 (a) and 11 (b) show the previous field and the current field, respectively.

Second, a subtracted signal is calculated from the previous field and the current field. The subtractor 902 subtracts the current field from all fields, and outputs a subtraction signal of only both components. Fig. 11C shows this subtraction signal.

Third, the motion area is detected from the subtracted signal. The motion detection unit 903 sets a region where the input subtracted signal exceeds a threshold value as a motion region, and outputs the width as a speed. Fig. 11D shows the movement area. As a result, the luminance reduction region can be set as the movement region. In addition, since the motion search such as two-dimensional block matching is not performed, for example, the circuit scale can be suppressed and the area and speed of the motion can be detected.

In addition, although it is used by the correction signal area limiting part 908 below, as shown in FIG. 11 (d), the area | region which matched the area | region of the width | variety same as the movement area with respect to the left and right of a movement area is called a movement area | region peripheral area | region. .

Fourth, apply LPF to the current field. The LPF 904 applies the LPF to the input current field and outputs it. Here, LPF is to calculate an average, and the number of taps is the speed output from the motion detection unit 903, but is not limited to this. 11 (e) shows the current field LPF pass signal.

Fifth, the current field LPF pass signal is subtracted from the current field. The subtractor 905 subtracts the current field LPF pass signal from the current field.

Sixth, the absolute value of the subtracted signal of the current field and the current field LPF pass signal is calculated. The absolute value calculator 906 calculates an absolute value of the subtracted signal of the current field and the current field LPF. 11 (f) shows the absolute value signal of the subtracted signal between the current field and the current field LPF.

Seventh, the LPF is applied to the absolute value signal output from the absolute value calculator 906. The LPF 907 applies the LPF to the absolute value signal output from the absolute value calculator 906 and outputs it. Here, LPF is to calculate an average, and the number of taps is the speed output from the motion detection unit 903, but is not limited to this. 11 (g) shows the LPF pass signal of the absolute value signal. This is the correction signal.

Eighthly, the correction signal is limited to only the area around the movement area. The correction signal region limiting unit 908 sets all correction signal values other than the movement region peripheral region to zero. Further, the LPF may be obscured so that the correction signal does not become discontinuous at the end of the area around the movement area. As a result, the correction can be performed only in a portion where the decrease in the luminance is large where the afterglow motion blur is easy to be noticeable.

9. The correction signal is subtracted from the current field. The subtractor 909 subtracts the correction signal output from the correction signal region limitation unit 908 from the current field. Fig. 11 (h) shows the current field after correction.

According to the third embodiment, the afterglow motion blur component around the luminance "reduced" region is calculated for an image signal of each color without using the direction of movement, and the image signal of "red, green" having a long afterglow time is calculated. It aims to reduce afterglow motion blur by "subtracting" the correction signal from the current field. At the same time, color shift can be reduced by this.

(Fourth Embodiment)

12 is a block diagram showing the configuration of the image display device of the fourth embodiment.

The fourth embodiment of the image display device of the present invention partially changes the third embodiment. Only this change is explained.

In the fourth embodiment, the afterglow motion blur component around the luminance "increase" region is calculated for the image signal of each color without using the direction of the movement, and for the image signal of "red, green" having a long afterglow time. It is an object to reduce afterglow motion blur by "adding" a correction signal to the current field. At the same time, an object thereof is to reduce color shift.

The difference of the structure from Embodiment 3 is demonstrated using FIG. 10 and FIG. In Embodiment 4, the subtractors 902 and 909 are changed into the subtractor 911 and the adder 912, respectively. Hereinafter, the detail is shown.

The change of the subtractor 902 is described. Reverse the object of subtraction. That is, the subtractor 911 subtracts all fields from the current field and outputs only a positive subtraction signal. By inputting this subtraction signal to the motion detection unit 903, it is possible to make the area around the luminance increase area a motion area.

The change of the subtractor 909 is described. Subtractor 909 is changed to adder 912. As a result, a correction signal can be added to the luminance increasing region in which afterglow is insufficient, the blur caused by the afterglow can be reduced, and the color shift can be reduced.

According to the fourth embodiment, the afterglow motion blur component around the luminance "increase" region is calculated for an image signal of each color without using the direction of the movement, and the image signal of "red, green" having a long afterglow time is calculated. By "adding" a correction signal to the current field, it is an object to reduce afterglow motion blur. At the same time, color shift can be reduced by this.

In Embodiments 1 to 4, the motion detection unit, the asymmetric gain, the LPF, and the like may be expanded in two dimensions and two-dimensional correction may be performed.

In addition, in all of the above embodiments 1 to 4, after the final correction or addition correction (corresponding to the correction unit 4 in FIG. 4 in the basic form), the red and green image signals become values outside the variable range. , Lack of correction, i.e., afterglow motion blur may not be erased. If it is 8 bits, the corrected image signal is negative or 255 or more.

This can simply be clipped to within 0 to 255, that is, a negative value of 0 and a value of 255 or more may be output as 255.

In addition, the absolute value of the undercorrection component (larger to red and green) is added to the blue image signal without clipping and, for example, afterglow motion blur does not occur, and the luminance is increased. You may subtract in the area vicinity and use it in order to improve "color shift."

However, at this time, if the place where the color shift does not occur is corrected, unnecessary correction is performed. Therefore, it is assumed that the color shift has occurred.

Therefore, in all of the above embodiments 1 to 4, the correction signal is also calculated for the blue image signal, and it is limited so as not to perform correction exceeding the correction signal for the blue. This makes it possible to operate this function only when color shift occurs. In the first and third embodiments, the correction is performed around the luminance reduction region, and in the second and fourth embodiments, the correction is performed around the luminance increase region, but these may be combined.

In addition, in the first to fourth embodiments, red and green image signals are corrected, but the present invention is not limited thereto. For example, as described in Patent Literature 1, a blue image signal may be corrected. . In this case, however, the afterglow motion blur is not improved, but the color shift is improved. At this time, by using the "direction of movement", it becomes possible to correct more accurately than the patent document 1.

Hereinafter, in the case of "correction of the blue image signal using the direction of movement around the luminance reduction area", "correction of the blue image signal of the vicinity of the luminance increase area using the direction of movement" is performed. Each case is demonstrated. The image display device in the case of "correcting with a blue image signal using the direction of movement about the periphery of the luminance reduction area" partially changes the first embodiment. Only this change is explained.

In this image display device, afterglow motion blur components around the luminance "reduced" region are calculated for image signals of each color, and a correction signal is "added" to the current field for a short "blue" image signal of afterglow time. This aims to reduce color shift.

The configuration difference from Embodiment 1 is demonstrated using FIG.

In this case, the LPF 604, the asymmetric gain calculator 605, and the subtractor 608 are changed. Hereinafter, the detail is shown.

Delete the LPF 604. This is because, in the case of correcting with a "blue" image signal, correction only needs to be performed in the moving region as in the region 412 of FIG. 3, so that a process of spatially widening the subtracted signal is not necessary.

The change of the asymmetric gain calculation part 605 is demonstrated. The asymmetric gain is taken as a gain that can be corrected, for example, as in the region 412 of FIG. When the correction is performed by the "blue" image signal around the luminance reduction area, the correction signal shape needs to be the same as the area 412 of FIG. 3, for example, which is corrected in red and green. The correction signal shape 410 is different from the case. Therefore, it is necessary to use asymmetric gains of different shapes.

The subtractor 608 is changed to an adder. This is to add a "blue" correction signal.

In this case, the afterglow motion blur component around the luminance "reduced" region is calculated for each color image signal, and the correction signal is "added" to the current field for the "blue" image signal having a short afterglow time. The variation can be reduced.

Next, the image display apparatus at the time of "correct | amending with a blue image signal using the direction of a movement with respect to the periphery of a luminance increase area | region" changes the same Embodiment 1 partially. Only this change is explained.

In this image display device, the afterglow motion blur component around the luminance "increase" region is calculated for the image signals of each color, and "subtract" the correction signal from the current field for the "blue" image signal having a short afterglow time. This aims to reduce color shift.

The difference of the structure from Embodiment 1 is demonstrated using FIG. In this case, the subtractor 602, the motion detector 603, the LPF 604, and the asymmetric gain calculator 605 are changed. Hereinafter, the detail is shown.

The subtractor 602 and the motion detector 603 perform the same changes as those in the second embodiment.

LPF 604 deletes. This is because, as described above, when the correction is performed by the "blue" image signal, since the correction is performed only in the moving region as in the region 413 of FIG. 3, the process of spatially widening the subtracted signal is not necessary. to be.

The change of the asymmetric gain calculation part 605 is demonstrated. The asymmetric gain is, for example, a gain that can be corrected as shown in 413 of FIG. 3. When the correction is performed by the "blue" image signal around the luminance increase area, the correction signal shape needs to be the same as the area 413 of FIG. 3, for example, which is corrected in red and green. It is different from the correction signal shape 411 in this case. Therefore, it is necessary to use asymmetric gains of different shapes.

In this case, the afterglow motion blur component around the luminance "increase" region is calculated for each color image signal, and the correction signal is "subtracted" from the current field for the "blue" image signal having a short afterglow time. The variation can be reduced.

(Other variations)

In addition, although this invention was demonstrated based on the said embodiment and modified example, of course, this invention is not limited to said embodiment. The following cases are also included in the present invention.

(1) Each of the above devices is specifically a computer system composed of a microprocessor, a ROM, a RAM, and the like. The computer program is stored in the RAM. As the microprocessor operates in accordance with the computer program, each device achieves its function. In this case, the computer program is configured by combining a plurality of command codes indicating instructions for the computer in order to achieve a predetermined function.

(2) Some or all of the components constituting the above devices may be configured by one system LSI (Large Scale Integration). The system LSI is a super-functional LSI manufactured by integrating a plurality of components on one chip, and specifically, is a computer system including a microprocessor, a ROM, a RAM, and the like. The computer program is stored in the RAM. By operating the microprocessor in accordance with the computer program, the system LSI achieves its function.

(3) Some or all of the components constituting each of the above devices may be constituted by an IC card or a single module detachable to each device. The IC card or the module is a computer system composed of a microprocessor, a ROM, a RAM, and the like. The IC card or the module may include the above ultra-functional LSI. By operating the microprocessor in accordance with a computer program, the IC card or the module achieves its function. This IC card or this module may have tamper resistance.

(4) The present invention may be the method shown above. Further, these methods may be computer programs that are realized by a computer, or may be digital signals formed of the computer programs. In addition, the present invention provides a computer-readable recording medium that can read the computer program or the digital signal, for example, a flexible disk, a hard disk, a CD-ROM, a MO, a DVD, a DVD-ROM, a DVD-RAM, a BD (Blu-). ray Disc), semiconductor memory, or the like.

The digital signal recorded on such a recording medium may be used.

In addition, the present invention may transmit the computer program or the digital signal via a telecommunication line, a wireless or wired communication line, a network representing the Internet, data broadcasting, or the like.

Moreover, this invention is a computer system provided with a microprocessor and a memory, The said memory may store the said computer program, and the said microprocessor may operate according to the said computer program.

Alternatively, the program or the digital signal may be recorded and transferred to the recording medium, or the program or the digital signal may be transferred via the network or the like to be executed by another independent computer system.

In addition, the present invention may be the method shown above.

Moreover, you may make it combine said embodiment and the said modified example, respectively.

The image display device and the image display method according to the present invention can reduce the motion blur of an image due to the afterglow component of the phosphor, and concomitantly improve the color shift. Thus, for example, a plasma display panel or the like. It is applicable to an image display apparatus using a phosphor having an afterglow time of.

Claims (18)

An image display apparatus for displaying an image using a phosphor having an afterglow time, Motion detection means for detecting motion information from an input image signal; Correction signal calculating means for calculating a correction signal for removing afterglow and motion blur caused due to movement of the image signal based on the motion information; Correction means for correcting the image signal by the correction signal, And the correction signal calculating means calculates, based on the motion information, the correction signal for further attenuating the image signal in a region where the value of the image signal decreases from a previous field. The method according to claim 1, And the correction signal calculating means calculates, based on the motion information, the correction signal for attenuating the image signal in a region where the value of the image signal decreases from a previous field and its surrounding region. Device. The method of claim 2, The motion detecting means detects a motion region of the image signal as the motion information, And said correction signal calculating means calculates said correction signal for attenuating said image signal in a region in which said value of said image signal decreases from a previous field and its surrounding region among said movement region and its surrounding region. Image display device. The method according to claim 1, The motion detecting means further calculates the speed of motion of the motion area, And the correction signal calculating means corrects the amount of change in the current field and all the fields of the image signal in the movement area and its surrounding area according to the speed of the movement, and calculates the corrected value as the correction signal. Image display device. The method of claim 4, And the correction signal calculating means corrects the amount of change by performing a low pass filter process with the number of taps corresponding to the speed of the movement. The method of claim 4, The motion detecting means further calculates a direction of motion of the motion area, And the correction signal calculating means corrects the amount of change asymmetrically according to the speed of the movement and the direction of the movement, and calculates the corrected value as the correction signal. The method of claim 6, The correction signal calculating means performs the low pass filter processing on the amount of change according to the number of taps corresponding to the speed of the movement, and asymmetrically in accordance with the direction of the movement with respect to the low pass filter pass signal subjected to the low pass filtering. And multiplying and correcting the signals created using two straight lines and one quadratic function. The method according to claim 1, The motion detecting means further calculates motion information reliability indicating the motion information about the motion area and the reliability of the motion information, And the correction signal calculating means attenuates the correction signal as the motion information reliability decreases. The method of claim 8, And the motion detecting means calculates the speed of the motion of the movement area as the motion information, and calculates the motion information reliability lower as the speed of the motion increases. The method of claim 8, And the motion detecting means calculates an error of the corresponding area of the current field and the previous field as the motion information, and calculates the motion information reliability lower as the error is larger. The method of claim 8, The motion detecting means calculates the error of the corresponding area of the current field and the previous field, and the error in the peripheral area of the corresponding area as the motion information, so that the smaller the difference between the two errors, the lower the reliability of the motion information. The image display device characterized by the above-mentioned. The method of claim 8, The motion detecting means calculates the speed and the direction of the motion of the motion area as the motion information, the speed of the motion and the direction of the motion, the speed of the motion and the motion of the peripheral area of the motion area. And the larger the difference in the direction of, the lower the reliability of the motion information. The method of claim 8, The motion detecting means calculates the speed and the direction of the motion of the motion area as the motion information, and calculates the speed of the motion and the direction of the motion, the speed of the motion and the motion of the corresponding area of all the fields. And the larger the difference in the direction, the lower the reliability of the motion information. An image display method for displaying an image using a phosphor having an afterglow time, A motion detection step of detecting motion information from an input image signal; A correction signal calculating step of calculating a correction signal for removing afterglow and motion blur caused due to movement of the image signal based on the motion information; A correction step of correcting the image signal by the correction signal, And in the correction signal calculating step, calculating the correction signal for further attenuating the image signal on the basis of the motion information in a region where the value of the image signal decreases from the previous field. A plasma display panel device for displaying an image using a phosphor having an afterglow time, Motion detection means for detecting motion information from an input image signal; Correction signal calculating means for calculating a correction signal for removing afterglow and motion blur caused due to movement of the image signal based on the motion information; Correction means for correcting the image signal by the correction signal, And said correction signal calculating means calculates said correction signal for further attenuating said image signal on the basis of said motion information for a region in which the value of said image signal decreases from a previous field. delete An integrated circuit for displaying an image using a phosphor having an afterglow time, Motion detection means for detecting motion information from an input image signal; Correction signal calculating means for calculating a correction signal for removing afterglow and motion blur caused due to movement of the image signal based on the motion information; Correction means for correcting the image signal by the correction signal, And the correction signal calculating means calculates, based on the motion information, the correction signal for further attenuating the image signal in a region where the value of the image signal is reduced from the previous field. A recording medium storing a program for displaying an image using a phosphor having an afterglow time, A motion detection step of detecting motion information from an input image signal; A correction signal calculating step of calculating a correction signal for removing afterglow and motion blur caused due to movement of the image signal based on the motion information; A program for causing a computer to execute a correction step of correcting the image signal by the correction signal, And in the correction signal calculating step, calculating the correction signal for further attenuating the image signal on the basis of the motion information in a region where the value of the image signal decreases from the previous field.

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